xilinx: zynqmp: Add missing prototype for zynqmp_mmio_write

Add missing prototype to fix the sparse warning, warning: no
previous prototype for 'zynqmp_mmio_write' [-Wmissing-prototypes].

Signed-off-by: Algapally Santosh Sagar <santoshsagar.algapally@amd.com>
Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma@amd.com>
Link: https://lore.kernel.org/r/20230301103334.1455-2-ashok.reddy.soma@amd.com
Signed-off-by: Michal Simek <michal.simek@amd.com>
diff --git a/drivers/mmc/zynq_sdhci.c b/drivers/mmc/zynq_sdhci.c
index 8b559d8..9dc3106 100644
--- a/drivers/mmc/zynq_sdhci.c
+++ b/drivers/mmc/zynq_sdhci.c
@@ -14,6 +14,7 @@
 #include "mmc_private.h"
 #include <log.h>
 #include <reset.h>
+#include <asm/arch/sys_proto.h>
 #include <dm/device_compat.h>
 #include <linux/err.h>
 #include <linux/libfdt.h>